Running water was cut off to Harbin, the capital of northeastern Heilongjiang province, for five days after a Nov. 13 explosion at a nearby chemical plant spewed toxins, including cancer-causing benzene, into the Songhua River.

Health Minister Gao Qiang said the incident highlighted a "major problem." Water was restored on Sunday and officials declared the water safe for drinking on Tuesday.

The spill was headed to the Russian city of Khabarovsk after flowing into the larger Heilong River, called the Amur in Russian. Chinese officials have said the spill was expected to reach Khabarovsk around Dec. 10-12, or sooner, AP reports.